The present disclosure relates to a liquid heating apparatus, and particularly, to an electronic thermostat for a liquid heating apparatus. More particularly, the present disclosure relates to an electronic thermostat that is suitable for use in an apparatus that dispenses heated beverages.
A liquid heating device, such as a coffee maker, has a heater that heats liquid, such as water, contained in a container. Mechanical switches are included in some liquid heating devices and are opened and closed to control the application of electrical power to the heater. Other liquid heating devices have solid-state switches that are operable to control the application of electrical power to the heater. Conventional mechanical switches have metal contacts with sufficient mass to serve as heat sinks to dissipate power, in the form of heat, caused by current flowing through the contacts when the mechanical switches are closed. However, mechanical switches have moving parts that wear out over time after repeated cycles of opening and closing. Electrical arcing, which degrades the metal contacts, often occurs when mechanical switches are opened and closed. Solid-state switches, such as triacs, do not have moving parts and therefore have long lives. However, solid-state switches sometimes require rather large heat sinks in order to dissipate power to prevent the solid-state switches from overheating.